Why'd I print the first row, third column? I was just demonstrating. It worked for me when I tested it, so I don't know why it does not work for you. Note that I changed the return from a hash to an array.

The whole idea is that you specify the matrix size in the call to the sub.

So, you are just learning? Play with the code a bit to see what happens. That's one of the best ways to learn.